Platelet Activating Factor (PAF), 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphocholine, represents a recently defined example of a class of biologically-active lipids active in the subnanomolar range and possessing a wide spectrum of pathophysiological effects. PAF promotes life-threatening anaphylactic reactions in animals and is suspected of mediating a range of allergic and inflammatory reactions in man. For example, PAF may be important in conditions such as asthma, adult respiratory distress syndrome and shock reactions. However, despite the increasing catalogue of conditions in which PAF maybe involved, greater insights into its role in health and disease ar hampered because precise and specific methods for its measurement are lacking. The capacity of PAF to aggregate platelets does not provide a suitable basis for strictly quantitative assay.
It would be desirable to develop an immunoassay for quantitative determination of PAF levels in blood serum. However, it has been found that PAF itself is insufficiently antigenic to produce the necessary PAF-antibodies needed for such an immunoassay.
Novel synthetic PAF analogues have now been found which are sufficiently antigenic to produce PAF-antibodies and a method suitable for the immunoassay of PAF levels in biological fluids has been developed.